The present invention relates generally to improvements in electronic shelf label (ESL) systems used in transaction establishments. More specifically, the present invention relates to improved methods and apparatus for replacing an ESL battery.
ESL systems typically include a plurality of ESLs for each merchandise item in a store. ESLs display the price of corresponding merchandise items on store shelves and are typically attached to a rail along the leading edge of the shelves. A store may contain thousands of ESLs to display the prices of the merchandise items. The ESLs are coupled to a central server where information about the ESLs is typically maintained in an ESL data file which contains ESL identification information and ESL merchandise item information. The central server sends messages, including price change messages, to the ESLs.
Typical ESLs include a battery which provides power for the display and electronic circuitry contained in the ESL, including power to maintain the display contents and ESL identification number information stored in volatile random access memory (RAM). One prior art ESL includes a single battery permanently sealed inside the ESL. This approach reduces the production cost of the ESL, but does not allow a user to replace the battery when its charge is exhausted. Another prior art ESL contains two batteries wired in parallel with a lockout mechanism which discourages the user from removing both batteries at the same time. While this approach allows the user to replace one of the batteries without losing the information stored in the volatile RAM, it also increases the cost of the ESL due to the requirement for two batteries.
The present invention advantageously provides methods and apparatus for improved electronic shelf label (ESL) battery replacement. A first embodiment of the present invention includes an ESL having a single battery and two battery compartments connected in parallel. A replacement battery is placed within the empty battery compartment before the old battery is removed. In a second embodiment of the present invention, an ESL includes a single battery situated in a single battery compartment, and a large value capacitor connected in parallel with the battery which maintains the contents of the ESL""s volatile RAM while the single battery is changed. In a third embodiment of the present invention, an ESL includes two battery compartments, a single battery and a large value capacitor connected in parallel with the battery compartments.
In another aspect, the present invention includes an ESL which displays instructions for changing the ESL battery. The ESL includes a pushbutton for user input which allows the user to cycle through multiple battery change instructions. These instructions may be stored locally in the ESL or may be transmitted to the ESL from a host system.
A more complete understanding of the present invention, as well as further features and advantages of the invention, will be apparent from the following detailed description and the accompanying drawings.